A Prince George’s County Circuit Court judge has rejected the latest effort of a former Prince George’s County homeland security official to challenge his involuntary manslaughter conviction for a 2007 incident in which he shot two furniture deliverymen, one fatally, at his Accokeek home.

Keith Washington, 52, can still request that a three-judge panel reduce his 45-year sentence, though prosecutors indicated at hearings in March that they reserved the right to oppose any reduction.

Prince George’s State’s Attorney Angela Alsobrooks said in a statement that she was pleased Washington “will remain behind bars.”

“Two innocent men are dead because Mr. Washington lost his temper,” she said. “He is a danger to all those around him and our community is safer without him walking our streets.”

Washington was convicted in 2008 of involuntary manslaughter and related charges in the slaying of 22-year-old Brandon Clark and the shooting and wounding of his cousin and co-worker, Robert White.

Prosecutors have accused the former county police officer and homeland security official of firing at the furniture deliverymen in January 2007 after a dispute about a set of bedrails that were being replaced at his home.

Washington has argued he acted in self defense, shooting at two much larger men who were attacking him. Over the years, he has mounted several legal challenges to his conviction and sentence — all of which have been rejected.

In this latest plea for “post-conviction relief” — which listed 23 problems with his trial and sentencing and took two days of testimony in March to sort out — Washington argued, essentially, that he was not adequately represented by lawyers during his trial and sentencing, and that prosecutors acted inappropriately.

Daniel Ginsburg, Washington’s attorney, said that his client’s trial lawyers — Michael Starr and Vincent Cohen — made a litany of mistakes during previous proceedings, including not calling a use-of-force expert to say that the physical evidence supported Washington’s version of events, and not adequately probing the injuries Washington suffered during the encounter. Ginsburg said physical evidence contradicted what Robert White told grand jurors and wrote in a media statement.

Prosecutors countered that most of those issues — especially those having to do with physical evidence and White’s statements — were already probed at Washington’s trial, and jurors still convicted him of involuntary manslaughter. At that trial, Assistant State’s Attorney Karen Polis argued, Washington was capably represented, noting that his lawyers objected 12 times during closing arguments and convinced jurors to acquit Washington of more serious charges, including second-degree murder and attempted second-degree murder.